The present invention relates to the field of textile industry, and particularly to wet treatment of textile filaments by washing and/or dyeing of the filaments, and has for its object a process of pre-drying the textile filaments after wet treatment.
The invention also has for its object a device for practicing this process.
Textile filaments are generally subjected, before their use, particularly for weaving, to washing and/or bleaching treatments as well as dyeing. These different treatments are carried out wet and have as a result excess moisture of the order of 100 to 300% by weight, and require a subsequent drying operation.
At present, this drying operation is carried out by supplying energy in the form of heat or radiation and/or an air current causing evaporation of the excess moisture. Such drying gives rise to a very high consumption of energy and, because of this, a high cost of production.
It is also known to perform mechanical spin-drying, particularly of skeins or bobbins, by means of centrifugal devices. In such a case, a residual moisture of 50% can be obtained very rapidly with low energy expenditure. However, these spin-drying processes are not useful in the framework of a continuous treatment of filaments, which is to say when the filaments pass continuously and are disposed in layers.
Finally, there is also known a process for expelling excess moisture with an over-pressure of air. Such an expulsion permits gains comparable to those obtained by mechanical drying. However, in the case of treatment of filaments in layers, such an expulsion process is not suitable, the filaments not being supported during treatment by an air jet and being at risk of becoming entangled under the influence of said jet.
The present invention has for its object to overcome these drawbacks by providing a process and a device for pre-drying of textile filaments after wet treatment, permitting obtaining optimum expulsion from a layer of filaments and ultimate drying which will be facilitated and relatively low cost.
To this end, the pre-drying process for textile filaments after wet treatment is characterized in that it consists essentially in applying simultaneously to a layer of wet filaments passing by on a conveyor with a permeable conveying surface, on the one hand, a mechanical squeeze-drying action and, on the other hand, a pressure differential by circulation of air through said layer.
The invention also has for its object a device for practicing this process, characterized in that it is essentially constituted by a conveyor for supporting the layer of filaments, with a permeable conveying surface, by a mechanical spin-drying means that acts on the layer of filaments passing by on the support conveyor, by means for applying a differential air pressure by circulation of air through said layer and by a chamber for recovering the expelled moisture having at its upper portion the support conveyor.